#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include <string>

//Screen attributes
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;

//The surfaces
SDL_Surface *background = NULL;
SDL_Surface *foo = NULL;
SDL_Surface *screen = NULL;

//The event structure
SDL_Event event;

SDL_Surface *load_image( std::string filename )
{
  //The image that's loaded
  SDL_Surface* loadedImage = NULL;

  //The optimized image that will be used
  SDL_Surface* optimizedImage = NULL;

  //Load the image
  loadedImage = IMG_Load( filename.c_str() );

  //If the image loaded
  if( loadedImage != NULL )
    {
      //Create an optimized image
      optimizedImage = SDL_DisplayFormat( loadedImage );

      //Free the old image
      SDL_FreeSurface( loadedImage );

      //If the image was optimized just fine
      if( optimizedImage != NULL )
        {
	  //Map the color key
	  Uint32 colorkey = SDL_MapRGB( optimizedImage->format, 0, 0xFF, 0xFF );

	  //Set all pixels of color R 0, G 0xFF, B 0xFF to be transparent
	  SDL_SetColorKey( optimizedImage, SDL_SRCCOLORKEY, colorkey );
        }
    }

  //Return the optimized image
  return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination )
{
  //Temporary rectangle to hold the offsets
  SDL_Rect offset;

  //Get the offsets
  offset.x = x;
  offset.y = y;

  //Blit the surface
  SDL_BlitSurface( source, NULL, destination, &offset );
}

bool init()
{
  //Initialize all SDL subsystems
  if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
    {
      return 1;
    }

  //Set up the screen
  screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );

  //If there was an error in setting up the screen
  if( screen == NULL )
    {
      return 1;
    }

  //Set the window caption
  SDL_WM_SetCaption( "\"Hello!\"", NULL );

  //If everything initialized fine
  return true;
}

bool load_files()
{
  //Load the background image
  background = load_image( "../../media/background.bmp" );

  //If the background didn't load
  if( background == NULL )
    {
      return false;
    }

  //Load the stick figure
  foo = load_image( "../../media/foo.png" );

  //If the stick figure didn't load
  if( foo == NULL )
    {
      return false;
    }

  return true;
}

void clean_up()
{
  //Free the surfaces
  SDL_FreeSurface( background );
  SDL_FreeSurface( foo );

  //Quit SDL
  SDL_Quit();
}

int main( int argc, char* args[] )
{
  //Quit flag
  bool quit = false;

  //Initialize
  if( init() == false )
    {
      return 1;
    }

  //Load the files
  if( load_files() == false )
    {
      return 1;
    }

  //Apply the surfaces to the screen
  apply_surface( 0, 0, background, screen );
    apply_surface( 320, 0, background, screen ); 
  apply_surface( 0, 240, background, screen ); 
  apply_surface( 320, 240, background, screen );

  apply_surface( 240, 190, foo, screen );

  //Update the screen
  if( SDL_Flip( screen ) == -1 )
    {
      return 1;
    }

  //While the user hasn't quit
  while( quit == false )
    {
      //While there's events to handle
      while( SDL_PollEvent( &event ) )
        {
	  //If the user has Xed out the window
	  if( event.type == SDL_QUIT )
            {
	      //Quit the program
	      quit = true;
            }
        }
    }

  //Free the surfaces and quit SDL
  clean_up();

  return 0;
}
